$ git clone -n https://src.fedoraproject.org/rpms/python-yarl.git /var/lib/mock/f43-build-60953843-6586745/root/chroot_tmpdir/scmroot/python-yarl
Cloning into '/var/lib/mock/f43-build-60953843-6586745/root/chroot_tmpdir/scmroot/python-yarl'...
$ git fetch origin 3c5c0ba163b8a4b42bde5bfdf699a14f3a5bf5d5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-yarl
 * [new ref]         3c5c0ba163b8a4b42bde5bfdf699a14f3a5bf5d5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3c5c0ba Remove cython upper version pin